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Unified Controllable and Faithful Text-to-CAD Generation with LLMs

35 points by PaulHoule

by hadlock

0 subcomment

I've had pretty good success with using LLMs to generate basic shapes using python and cadquery (which generates real parametric step files you can edit in fusion, not glorified triangulated STLs). Yesterday I had GPT5.5 build a python script to generate fender style Mandolin with separate neck and body, with correct bolt holes for the neck, gibson style bridge, and stop-tail, even fretboard with the little dots and cutouts for the fret wire (I didn't ask for these, but it added them anyways). Everything looks correct and to scale. I can pastebin the .py later if anyone is interested.

by avaer

2 subcomments

Text to CAD doesn't need papers. You can literally just try it and see that it works well with the frontier models. If you want reification/meshing I recommend [1] which is what Godot uses. You can throw the results in a physics engine in an afternoon and see for yourself.
This wasn't obvious a year ago, but today CAD literally reduces to Simon Wilson's pelican test, since CAD is largely a matter of functional CSG, and CSG is really not that different from SVG. It's just one more dimension, which it turns out is not a problem.
LLMs consistently one-shot CSG based video game levels with interesting physics puzzles (citing myself). Given this I'm willing to conclude that the frontier models are good at automated CAD if given the correct harness. But I guess a lot of people don't know this yet.
[1] https://github.com/elalish/manifold

by nancyminusone

0 subcomment

I don't think I've ever heard a mechanical engineer say "torus" in my life unless they're talking about the car. When you are doing feedback with a human operator you use terms like "make this thicker" or "rotate that this way" while pointing at them. Text does not have this.

by nisegami

0 subcomment

The only time text-to-SCAD has ever worked for me was when Claude (the app, not even Claude Code) decided spontaneously to spin up an environment and check the renderings of its SCAD code. That session lead to something 90-95% of the way to the finished product, and in some ways even surpassing my expectations by looking up measurements for relevant products instead of using placeholders.
Modifying the prompt and then trying it again did not lead to that self-verification loop and the output was unusable garbage.

by spiral09

0 subcomment